Impact resistance of fibre reinforced concrete containing lime sludge based composite cements

Abstract

The development of composite cements using supplementary cementitious materials is considered to be state of art in cement production. This paper presents the results of an experimental impact test conducted using drop weight hammer on fibre reinforced concrete (FRC) with 0.32 and 0.40 water/binder ratio made with binary and quaternary composite lime sludge cements. For this purpose, 34 concrete mixes containing hooked end steel fibres with aspect ratios of 50 at dosage of 0.5%, 1.0% and 1.5% were prepared with binary and quaternary cementitious systems. The binary systems were designed with various proportions of lime sludge ranging from 5%, 10% and 15%, while the quaternary systems were designed with various proportions of lime sludge combined with 15% of flyash and 10% of silica fume as partial substitute of cement. Further, a six regression models were constructed and validated for the assessment of effectiveness in determining the impact energy at first crack and failure. The results depict that replacement of 10% lime sludge in quaternary cementitious systems with this proportion is very effective in increasing the compressive strength and impact strength in concrete.